The Keithley 2001 is obsolete, so our test department is moving on to a Keysight. They'll have to add a driver into our Python library. They loaned me one to evaluate. https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 Not too bad, considering that my Fluke hasn't been calibrated in human memory. I had to take six pics to get the numbers on the Fluke. Its VF display heterodynes with my phone camera and makes a cool comet effect.
Two DVMs
Started by ●August 18, 2023
Reply by ●August 19, 20232023-08-19
On 2023/08/18 7:25 p.m., John Larkin wrote:> The Keithley 2001 is obsolete, so our test department is moving on to > a Keysight. They'll have to add a driver into our Python library. > > They loaned me one to evaluate. > > https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 > > Not too bad, considering that my Fluke hasn't been calibrated in human > memory. > > I had to take six pics to get the numbers on the Fluke. Its VF display > heterodynes with my phone camera and makes a cool comet effect. > >Is the Fluke meter not quite showing yet another digit in the photo? Might that be an 8 or 9 as the .00000X digit? If so, then indeed, it isn't doing badly! John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."
Reply by ●August 19, 20232023-08-19
On 8/19/2023 9:49 AM, John Robertson wrote:> On 2023/08/18 7:25 p.m., John Larkin wrote: >> The Keithley 2001 is obsolete, so our test department is moving on to >> a Keysight. They'll have to add a driver into our Python library. >> >> They loaned me one to evaluate. >> >> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 >> >> Not too bad, considering that my Fluke hasn't been calibrated in human >> memory. >> >> I had to take six pics to get the numbers on the Fluke. Its VF display >> heterodynes with my phone camera and makes a cool comet effect. >> >> > > Is the Fluke meter not quite showing yet another digit in the photo? > Might that be an 8 or 9 as the .00000X digit? > > If so, then indeed, it isn't doing badly! > > John :-#)#Maybe it's the Keysight that's off by ~10 uV :-) Ed
Reply by ●August 19, 20232023-08-19
On Sat, 19 Aug 2023 12:43:24 -0400, ehsjr <ehsjr@verizon.net> wrote:>On 8/19/2023 9:49 AM, John Robertson wrote: >> On 2023/08/18 7:25 p.m., John Larkin wrote: >>> The Keithley 2001 is obsolete, so our test department is moving on to >>> a Keysight. They'll have to add a driver into our Python library. >>> >>> They loaned me one to evaluate. >>> >>> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 >>> >>> Not too bad, considering that my Fluke hasn't been calibrated in human >>> memory. >>> >>> I had to take six pics to get the numbers on the Fluke. Its VF display >>> heterodynes with my phone camera and makes a cool comet effect. >>> >>> >> >> Is the Fluke meter not quite showing yet another digit in the photo? >> Might that be an 8 or 9 as the .00000X digit? >> >> If so, then indeed, it isn't doing badly! >> >> John :-#)# > >Maybe it's the Keysight that's off by ~10 uV >:-) > >EdI think there was one more digit that the phone camera missed. But they agree to 1 PPM! I have a request to design a board that will be a couple-of-PPM accurate programmable voltage source. That's scary. I'm thinking of using several (or many) ADR420-series parts, temperature controlled. Or a few LM199s, except it's obsolete. ADR1000 is still available. REF-01 is remarkably stable. I wonder what those DVMs use.
Reply by ●August 19, 20232023-08-19
On Sat, 19 Aug 2023 10:11:57 -0700, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:>On Sat, 19 Aug 2023 12:43:24 -0400, ehsjr <ehsjr@verizon.net> wrote: > >>On 8/19/2023 9:49 AM, John Robertson wrote: >>> On 2023/08/18 7:25 p.m., John Larkin wrote: >>>> The Keithley 2001 is obsolete, so our test department is moving on to >>>> a Keysight. They'll have to add a driver into our Python library. >>>> >>>> They loaned me one to evaluate. >>>> >>>> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 >>>> >>>> Not too bad, considering that my Fluke hasn't been calibrated in human >>>> memory. >>>> >>>> I had to take six pics to get the numbers on the Fluke. Its VF display >>>> heterodynes with my phone camera and makes a cool comet effect. >>>> >>>> >>> >>> Is the Fluke meter not quite showing yet another digit in the photo? >>> Might that be an 8 or 9 as the .00000X digit? >>> >>> If so, then indeed, it isn't doing badly! >>> >>> John :-#)# >> >>Maybe it's the Keysight that's off by ~10 uV >>:-) >> >>Ed > >I think there was one more digit that the phone camera missed. > >But they agree to 1 PPM! > >I have a request to design a board that will be a couple-of-PPM >accurate programmable voltage source. That's scary. > >I'm thinking of using several (or many) ADR420-series parts, >temperature controlled. Or a few LM199s, except it's obsolete. > >ADR1000 is still available. > >REF-01 is remarkably stable. > >I wonder what those DVMs use. > >The Fluke uses a "reference transistor", which is an NPN with a zener in the emitter.
Reply by ●August 19, 20232023-08-19
John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:> On Sat, 19 Aug 2023 10:11:57 -0700, John Larkin > <jlarkin@highlandSNIPMEtechnology.com> wrote: > >> On Sat, 19 Aug 2023 12:43:24 -0400, ehsjr <ehsjr@verizon.net> wrote: >> >>> On 8/19/2023 9:49 AM, John Robertson wrote: >>>> On 2023/08/18 7:25 p.m., John Larkin wrote: >>>>> The Keithley 2001 is obsolete, so our test department is moving on to >>>>> a Keysight. They'll have to add a driver into our Python library. >>>>> >>>>> They loaned me one to evaluate. >>>>> >>>>> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 >>>>> >>>>> Not too bad, considering that my Fluke hasn't been calibrated in human >>>>> memory. >>>>> >>>>> I had to take six pics to get the numbers on the Fluke. Its VF display >>>>> heterodynes with my phone camera and makes a cool comet effect. >>>>> >>>>> >>>> >>>> Is the Fluke meter not quite showing yet another digit in the photo? >>>> Might that be an 8 or 9 as the .00000X digit? >>>> >>>> If so, then indeed, it isn't doing badly! >>>> >>>> John :-#)# >>> >>> Maybe it's the Keysight that's off by ~10 uV >>> :-) >>> >>> Ed >> >> I think there was one more digit that the phone camera missed. >> >> But they agree to 1 PPM! >> >> I have a request to design a board that will be a couple-of-PPM >> accurate programmable voltage source. That's scary. >> >> I'm thinking of using several (or many) ADR420-series parts, >> temperature controlled. Or a few LM199s, except it's obsolete. >> >> ADR1000 is still available. >> >> REF-01 is remarkably stable. >> >> I wonder what those DVMs use. >> >> > > The Fluke uses a "reference transistor", which is an NPN with a zener > in the emitter. > >At a SWAG, three LTZ1000s and some software. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
Reply by ●August 19, 20232023-08-19
On Saturday, August 19, 2023 at 1:24:16 PM UTC-4, John Larkin wrote:> On Sat, 19 Aug 2023 10:11:57 -0700, John Larkin > <jla...@highlandSNIPMEtechnology.com> wrote: > > >On Sat, 19 Aug 2023 12:43:24 -0400, ehsjr <eh...@verizon.net> wrote: > > > >>On 8/19/2023 9:49 AM, John Robertson wrote: > >>> On 2023/08/18 7:25 p.m., John Larkin wrote: > >>>> The Keithley 2001 is obsolete, so our test department is moving on to > >>>> a Keysight. They'll have to add a driver into our Python library. > >>>> > >>>> They loaned me one to evaluate. > >>>> > >>>> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 > >>>> > >>>> Not too bad, considering that my Fluke hasn't been calibrated in human > >>>> memory. > >>>> > >>>> I had to take six pics to get the numbers on the Fluke. Its VF display > >>>> heterodynes with my phone camera and makes a cool comet effect. > >>>> > >>>> > >>> > >>> Is the Fluke meter not quite showing yet another digit in the photo? > >>> Might that be an 8 or 9 as the .00000X digit? > >>> > >>> If so, then indeed, it isn't doing badly! > >>> > >>> John :-#)# > >> > >>Maybe it's the Keysight that's off by ~10 uV > >>:-) > >> > >>Ed > > > >I think there was one more digit that the phone camera missed. > > > >But they agree to 1 PPM! > > > >I have a request to design a board that will be a couple-of-PPM > >accurate programmable voltage source. That's scary. > > > >I'm thinking of using several (or many) ADR420-series parts, > >temperature controlled. Or a few LM199s, except it's obsolete. > > > >ADR1000 is still available. > > > >REF-01 is remarkably stable. > > > >I wonder what those DVMs use. > > > > > The Fluke uses a "reference transistor", which is an NPN with a zener > in the emitter.I seriously bet that's using 'mathematical' compensation of some kind.
Reply by ●August 19, 20232023-08-19
On Sat, 19 Aug 2023 17:49:52 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote: >> On Sat, 19 Aug 2023 10:11:57 -0700, John Larkin >> <jlarkin@highlandSNIPMEtechnology.com> wrote: >> >>> On Sat, 19 Aug 2023 12:43:24 -0400, ehsjr <ehsjr@verizon.net> wrote: >>> >>>> On 8/19/2023 9:49 AM, John Robertson wrote: >>>>> On 2023/08/18 7:25 p.m., John Larkin wrote: >>>>>> The Keithley 2001 is obsolete, so our test department is moving on to >>>>>> a Keysight. They'll have to add a driver into our Python library. >>>>>> >>>>>> They loaned me one to evaluate. >>>>>> >>>>>> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 >>>>>> >>>>>> Not too bad, considering that my Fluke hasn't been calibrated in human >>>>>> memory. >>>>>> >>>>>> I had to take six pics to get the numbers on the Fluke. Its VF display >>>>>> heterodynes with my phone camera and makes a cool comet effect. >>>>>> >>>>>> >>>>> >>>>> Is the Fluke meter not quite showing yet another digit in the photo? >>>>> Might that be an 8 or 9 as the .00000X digit? >>>>> >>>>> If so, then indeed, it isn't doing badly! >>>>> >>>>> John :-#)# >>>> >>>> Maybe it's the Keysight that's off by ~10 uV >>>> :-) >>>> >>>> Ed >>> >>> I think there was one more digit that the phone camera missed. >>> >>> But they agree to 1 PPM! >>> >>> I have a request to design a board that will be a couple-of-PPM >>> accurate programmable voltage source. That's scary. >>> >>> I'm thinking of using several (or many) ADR420-series parts, >>> temperature controlled. Or a few LM199s, except it's obsolete. >>> >>> ADR1000 is still available. >>> >>> REF-01 is remarkably stable. >>> >>> I wonder what those DVMs use. >>> >>> >> >> The Fluke uses a "reference transistor", which is an NPN with a zener >> in the emitter. >> >> > >At a SWAG, three LTZ1000s and some software. > >Cheers > >Phil HobbsGreat longterm stability. Maybe they've been aged. $93 from Digikey.
Reply by ●August 19, 20232023-08-19
On Sat, 19 Aug 2023 11:04:25 -0700 (PDT), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:>On Saturday, August 19, 2023 at 1:24:16?PM UTC-4, John Larkin wrote: >> On Sat, 19 Aug 2023 10:11:57 -0700, John Larkin >> <jla...@highlandSNIPMEtechnology.com> wrote: >> >> >On Sat, 19 Aug 2023 12:43:24 -0400, ehsjr <eh...@verizon.net> wrote: >> > >> >>On 8/19/2023 9:49 AM, John Robertson wrote: >> >>> On 2023/08/18 7:25 p.m., John Larkin wrote: >> >>>> The Keithley 2001 is obsolete, so our test department is moving on to >> >>>> a Keysight. They'll have to add a driver into our Python library. >> >>>> >> >>>> They loaned me one to evaluate. >> >>>> >> >>>> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 >> >>>> >> >>>> Not too bad, considering that my Fluke hasn't been calibrated in human >> >>>> memory. >> >>>> >> >>>> I had to take six pics to get the numbers on the Fluke. Its VF display >> >>>> heterodynes with my phone camera and makes a cool comet effect. >> >>>> >> >>>> >> >>> >> >>> Is the Fluke meter not quite showing yet another digit in the photo? >> >>> Might that be an 8 or 9 as the .00000X digit? >> >>> >> >>> If so, then indeed, it isn't doing badly! >> >>> >> >>> John :-#)# >> >> >> >>Maybe it's the Keysight that's off by ~10 uV >> >>:-) >> >> >> >>Ed >> > >> >I think there was one more digit that the phone camera missed. >> > >> >But they agree to 1 PPM! >> > >> >I have a request to design a board that will be a couple-of-PPM >> >accurate programmable voltage source. That's scary. >> > >> >I'm thinking of using several (or many) ADR420-series parts, >> >temperature controlled. Or a few LM199s, except it's obsolete. >> > >> >ADR1000 is still available. >> > >> >REF-01 is remarkably stable. >> > >> >I wonder what those DVMs use. >> > >> > >> The Fluke uses a "reference transistor", which is an NPN with a zener >> in the emitter. > >I seriously bet that's using 'mathematical' compensation of some kind.It's just a transistor and a zener. The trick with reference transistors was to select a resistor to tweak the operating current to get the tempco to zero. That's a nuisance in production. If I ovenize my references, the tweak could be automated, whatever part I use.
Reply by ●August 19, 20232023-08-19
On 2023-08-19 14:43, John Larkin wrote:> On Sat, 19 Aug 2023 17:49:52 -0000 (UTC), Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote: >>> On Sat, 19 Aug 2023 10:11:57 -0700, John Larkin >>> <jlarkin@highlandSNIPMEtechnology.com> wrote: >>> >>>> On Sat, 19 Aug 2023 12:43:24 -0400, ehsjr <ehsjr@verizon.net> wrote: >>>> >>>>> On 8/19/2023 9:49 AM, John Robertson wrote: >>>>>> On 2023/08/18 7:25 p.m., John Larkin wrote: >>>>>>> The Keithley 2001 is obsolete, so our test department is moving on to >>>>>>> a Keysight. They'll have to add a driver into our Python library. >>>>>>> >>>>>>> They loaned me one to evaluate. >>>>>>> >>>>>>> https://www.dropbox.com/scl/fi/vv1u2r1whendlxioihoma/Two_DVMs.jpg?rlkey=y0pbb1xhjl5na4004lfjoih6c&raw=1 >>>>>>> >>>>>>> Not too bad, considering that my Fluke hasn't been calibrated in human >>>>>>> memory. >>>>>>> >>>>>>> I had to take six pics to get the numbers on the Fluke. Its VF display >>>>>>> heterodynes with my phone camera and makes a cool comet effect. >>>>>>> >>>>>>> >>>>>> >>>>>> Is the Fluke meter not quite showing yet another digit in the photo? >>>>>> Might that be an 8 or 9 as the .00000X digit? >>>>>> >>>>>> If so, then indeed, it isn't doing badly! >>>>>> >>>>>> John :-#)# >>>>> >>>>> Maybe it's the Keysight that's off by ~10 uV >>>>> :-) >>>>> >>>>> Ed >>>> >>>> I think there was one more digit that the phone camera missed. >>>> >>>> But they agree to 1 PPM! >>>> >>>> I have a request to design a board that will be a couple-of-PPM >>>> accurate programmable voltage source. That's scary. >>>> >>>> I'm thinking of using several (or many) ADR420-series parts, >>>> temperature controlled. Or a few LM199s, except it's obsolete. >>>> >>>> ADR1000 is still available. >>>> >>>> REF-01 is remarkably stable. >>>> >>>> I wonder what those DVMs use. >>>> >>>> >>> >>> The Fluke uses a "reference transistor", which is an NPN with a zener >>> in the emitter. >>> >>> >> >> At a SWAG, three LTZ1000s and some software. >> >> Cheers >> >> Phil Hobbs > > Great longterm stability. Maybe they've been aged. > > $93 from Digikey. >Could be. They're probably a bit cheaper if you buy lots at a time, but there's obviously a lot of TLC involved. Stabilizing the temperature adequately will require some care, for sure. I sometimes put voltage references on paddles routed out of the PCB. This is mostly to avoid shifts due to mechanical stress on the package, but could come in very handy to (more or less) eliminate temperature gradients. A nice analytically-calculable geometry, e.g. a paddle within a paddle, joined with two pairs of thin bars, would let one put two nested temperature control zones in a small space. Some nice squeaky styrofoam, and maybe a bit of wraparound metal here and there to get rid of incidental vertical gradients, would probably do a good job. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
